1. Field of the Invention
The present invention relates to an optical flexible printed circuit board; and, more particularly, to an optical flexible printed circuit board which includes an optical waveguide pattern disposed on a partial region and an insulating layer with a surface profile by the optical waveguide pattern, and a method for manufacturing the same.
2. Description of the Related Art
As a printed circuit board technology employing conventional cupper-based electric wires fails to satisfy requirements of high-speed and high-capacity of data in electronic parts, a rapid research has recently been conducted on an optical flexible printed circuit board.
An optical flexible printed circuit board includes an optical waveguide for transmission of optical signals, and metal wires for transmission of electrical signals, so that it is possible to increase a bandwidth of data transfer, reduce power consumed during long-distance transmission, and increase wiring density.
As such, an optical flexible printed circuit board has been manufactured by lamination of an optical waveguide layer and a metal wiring layer which can transmit and receive signal in a format of rays by using polymer and optical fibers.
However, in case where an optical flexible printed circuit board is manufacture by lamination of the optical waveguide layer and the metal wiring layer, an increase in the board's thickness may increase bending rigidity of the board itself. Thus, in case where the board is warped, bending stresses applied to edge surfaces of the board (i.e., upper surface and lower surface of the board) are higher than those of its center.
In this case, lamination of the optical waveguide pattern and the metal wire layers makes them closer to upper and lower surfaces than the center of the board, that is, edge surfaces, and thus the layers may be damaged by bending stresses. Therefore, it is a need to develop an optical flexible printed circuit board with a bending reliability.